Lamp assembly means



1934- l H. A. DOUGLAS 1,946,197

LAMP ASSEMBLY MEANS Filed Jan. 50, 1931 2 Sheets-Sheet l 1934- H. A. DOUGLAS LAMP ASSEMBLY MEANS Filed Jan. 50, 1931 2 Sheets-Sheet 2 Patented Feb. 6, 1934 LAMP ASSEMBLY MEANS Harry A. Douglas, Bronson, Mich.

Application January 30, 1931. Serial No. 512,374

I 7 Claims. (01. 240-411) is inclusive of cylindrical metal lamp sockets 5,

My invention relates to assembly means for incandescent electric lamps and their mountings and is of particular service Where such mountings are in the form of concave reflectors for automobile headlights an.dthe lamps are assembled therewith by means inclusive of sockets. The reflectors are desirably parabolic having openings therethrough through which the sockets project.

Among other objects my invention aims to provide improved means for assuring the assembly of the parts in only one way so that the lamps will be properly focused, and, when so focused, maintaining said proper focus with a minimum of bearing points upon the reflector.

In one aspect, my invention contemplates means whereby the socket, when assembled with the reflector, is prevented from being moved out or" position by manipulation of the lamp, thus guarding against displacement of the socket when the lamp is inserted or removed.

The invention may be understood by reference to the illustrative construction shown in the accompanying drawings, in which- Figure 1 is a View showing an incandescent lamp and circuit contact terminals in elevation and associated parts in section, of the illustrated embodiment of the invention;

Figure 2 is a side elevation of the socket and a portion of the lamp base, showing associated parts in section;

Figure 3 is a section taken on the line 3-3 of Figure 2; i

Figure 4 is a section taken on the line 4--4 of Figure 3;

Figure 5 is a sectional View of a complete automobile headlight embodying the illustrative construction of my invention;

Figure 6 is a sectional view taken on the line 66 of Figure l; and

Figure 7 is a perspective View illustrating some parts in separated relation.

The headlight here shown for illustration is inclusive of a parabolic reflector of thin metal 1 whose reflecting face is covered by a light transmitting closure 2 which may be or" glass. This closure is held against the front of the reflector by an assembling ring 3 which also serves to assemble the reflector with a concave back i. The construction of the peripheral rim portion of the reflector with the back and the construction of the parts 3 and i may be of any well known or suitable character and form no novel parts in my present invention, on which account further description of these parts need not be given.

The embodiment of the invention illustrated each adapted to be passed, through a circular opening in the reflector. Oneof suchopenings 6 in the reflector may be located in the crown of the reflector, and one of the sockets 5 passed therethrough. The opening 6 in the crown of the reflector is essentially circular and of the diameter of the socket 5 to receive the socket snugly and may be concentric with the principal axis of the reflector. In assembling the socketwith the reflector, an inward extension 7 of the portion of the reflector margining the opening 6 passes through the bayonet channel 8, and ultimately, by manipulation of the socket, is received in the innermost seat 9 of the bayonet channel 8. Lugs 10, formed by striking portions of the socket 5 outwardly, are so located on the socket as to pass through lateral enlargements 11 of the opening 6, when the extension '7 is passing through the channel 8. When the extension? is seated in the seat 9 and the axis of the socket is coincident with the axis of the reflector, the lugs bear against the reflecting face of the reflector-in a plane common to the seat 9 and which plane is perpendicular to the axis of the socket. The lugs 10 together with the seat 9 are'thus distributed around the axis of the socket to provide bearing points for the socket on the reflecting surface of the reflector less than 180 degrees apart, in this instance substantially 120 degrees apart, determining, when the bearing points are pressed against the reflector, a position of the socket normal to the reflector.

In assembling the socket 5 with the reflector, the socket is moved through the opening 6 against the pressure of a spring which is here shown as including a plate 12 having three in: tegral elliptic legs 13. The spring plate 12 has a central aperture 14 which is essentially circular of substantially the diameter of the socket 5. The portion of the plate 12 margining the aperture '14 is inwardly extended as at 15 and these extensions 15 seat in recesses 16 in the rear end of the socket 5. The spring is thus locked to the socket in a plane perpendicular to the socket axis. One of these extensions 15 is desirably larger arcuately than the other two to snugly lit a correspondingly larger recess in the socket, for a purpose presently explained. An insulating contact carrier in the form of a disc 17 is shownof substantially the size of the bore ofthe socket- 5. This disc 17 has segmental shoulders 18 which correspond to the recesses 16 in the rear of the socket 5. When first the plate 12 has. its exten sions 15 located in the recesses Y16 and then the disc 17 is located in the bore of the socket outwardly of the plate 12, with the shoulder portions 18 also in the recesses 16, fingers 19 extending longitudinally from the rear end of the socket are turned down to lap the disc 1'7, holding the disc and plate in place.

The legs 13 of the spring are bent around upon themselves and have free ends which describe a reverse curve. The terminations 13a of the free ends of the legs 13 are turned toward the forward end of the socket, each to provide a bearing point at which the spring presses against the reflector, which bearing points are radially aligned with the bearing points 9, 10, 10 of the socket, as best illustrated in Figure 3. When the socket 5 has been passed through the opening 6 against the pressure of the spring and the extension '7 of the reflector located in the seat 9, with the lugs 10, 10 bearing against the reflecting face of the reflector, the legs 13 of the spring are tensioned against the rear surface of the reflector at points close to the socket 5. The legs 13 are desirably so disposed that when the socket is in final position, the terminations 13a of the legs 13 have been moved toward the socket and press against the rear surface of the reflector at points longitudinally as well as radially aligned with the bearing points 9, 10, 10 of the socket, as best illustrated in Figures 1 and 2. In other words, the legs 13 press against the reflector each at a point substantially directly behind each point 9, 10, 10 (that is, in a plane parallel to the axes of the socket) and the reflector is clamped between the points 9, 10, 10 and the terminations 13a of the legs 13, thus preventing the socket axis from being thrown out of line with the reflector axis as might occur if the spring legs pressed against a portion of the reflector substantially more remote from the socket axis than the bearing points of the socket on the reflector. Furthermore, the reflector is prevented from being dented as frequently occurs when the spring presses against a portion of the reflector which is not being pressed from the other side. Such dents are objectionable since they cause slight humps upon the reflecting face of the reflector which in turn cause distortion of the light beams. Since the spring presses the socket in a plane perpendicular to the socket axis, the socket is maintained normal to the reflector, as well as being positioned axially with respect thereto.

When one of the sockets 5 is located in the crown of the reflector, as shown in Figure 1, its axis may be maintained coincident with the principal axis of the reflector, as already set forth. This result may be further insured, if desired, by flattening a relatively small area of the crown surrounding the socket, in a plane perpendicular to the reflector axis, as shown in the drawings.

In the location in the crown of the reflector, the socket may receive an incandescent lamp 20 having the cylindrical base 21 which is received in the bore of the socket. The base 21 is conveniently provided with lateral enlargements such as the bayonet pins 22, one of which passes through the bayonet channel 8 in the socket and is received in the intermediate seat 23 of the slot 8, while the other bayonet pin passes The lamp 20 is in this instance a double pole lamp where filament 26 is the bright light producing filament of the lamp, one terminal of which is connected with one of the lamp contacts 27 upon the rear of the lamp base. A filament 28 which is the dim light producing filament of the lamp, is included between the other of the lamp contacts 27 and a metallic sheath which constitutes a part of the lamp base and to which the filament 26 is also connected. By suitable switching mechanism, not illustrated, either the filaments 26 or 28 may be included in circuit or both may be excluded from circuit. Each circuit terminal contact 29 is pressed against its complemental lamp contact 27 to secure the mechanical assembly of the lamp with the socket and also to complete the lamp circuit at the reflector.

One of the shoulder portions 18 of the insulating disc 17 and its corresponding recess in the socket are here shown wider than the others so that the disc 17 can be assembled in only one position rotatively with respect to the socket. Thus the terminal contacts 29 are positively positioned in longitudinal alignment with the lamp contacts 27.

Each terminal contact 29, which is conventionally connected with an insulated current conducting wire 30, is pressed forwardly by a helical coiled spring 31 which surrounds the corresponding stem continuation 32 of each contact 29. Each stem 32 slides within a spring barrel 33 formed integrally with a metallic sleeve 33a carried by the insulating disc 17. The spring 31 presses at one end against the base of the barrel 33 and the other end against a shoulder formed between the contact 29 and the stem 32. Since the lamp base is inserted in the socket against the pressure of the springs 31, the springs 31 press the bayonet pins 22 into engagement with the seats 23 and 25.

The seats 23 and 25 are spaced from the focus of the reflector a distance equal to the distance between the bayonet pins 22 and the lighting center of the bright light producing filament of the lamp 20. The lighting center of the bright light producing filament 26 of the lamp 20 which is shown upon the axis of the socket when the parts are properly assembled is thus placed exactly upon the focus of the reflector when the bayonet pins 22 are properly seated for the reasons hereinbefore set forth. a

When one of the sockets 5 is located to one side of the principal axis of the reflector, it may be provided with a single terminal contact stem 34 connected with an insulated wire 35 and adapted to be pressed against a single contact on the base of the single pole lamp 36, the lamp being included in circuit by being grounded similarly to the lamp 20, as already described.

The wires 30 and 35 may be carried through the concave back 4 of the headlight to a plugging-in device by which the lamps may be connected with a source of current not shown.

Means are desirably provided for securing the proper intimacy of the lamp base and the socket to further insure coincidence of the lighting center of the lamp filament and the reflector focus, guarding against variations caused by slight differences between the diameters of the bases and the bore of the socket common in commercial practice. In this instance, the wall of the socket 5 is split longitudinally as at 37, allowing a slight give to the socket and at the same time, since the socket is formed of resilient metal, providing a segmental portion 38 of the socket which functions somewhat as a spring tongue. The spring tongue 38 is further defined by the bayonet channel 8. The socket is further formed, as shown, with internal longitudinal ribs 39 and 40 spaced substantially 120 degrees apart, and a projection 41 located on the spring tongue 38 and 120 degrees from each of the ribs 39 and 40. When the base 21 of the lamp 20, for instance, is inserted in the socket 5, the base 21 will be pressed against the ribs 39 and 40 by the spring tongue 38 through the intermediation of the projection 41 on said tongue. Thus a three point bearing is provided for the lamp base in the socket which positions the axis of the lamp substantially exactly upon the axis of the socket regardless of slight variations in the diameters of the lamp bases used. The projection 41 is shown at an intermediate point longitudinally of the socket, and desirably mid-way between the {inner and outer ends of the ribs 39 and 40, so that the base will be pressed uniformly against the entire length of the ribs 39 and 40. Features of the socket just described and not herein claimed, are shown and claimed in my copending applications Ser. No. 512,375 filed January 30, 1931; and Serial No. 512,376, flled January 30, 1931.

The extension 7 of the reflector and the bayonet channel 8 receiving the extension 7, are desirably wider than the bayonet channel 24, so that the socket can be assembled with the reflector in only one way, thus guarding against incorrect assembly, and since the extension 7 must be received in the seat 9 to lock the socket to the reflector, the.

socket can be assembled in only one position rotatively with respect to the reflector.

The socket desirably cannot be positioned in the reflector with the spring legs 13 bearing against the reflecting face of the reflector.

Obviously, when the extension 7 is seated in the seat 9, the socket cannot be rotated by manipulation of the lamp. It will thus be seen that by my improved assembly means all of the parts, from the terminal contacts in the rear, to the lamp filament in front, are positively aligned with their respective cooperating elements, and the common axis of the parts is positioned and maintained normal tothe reflector with a minimum of parts and a minimum of bearing points upon the reflector.

Such changes may be made as fall within the scope of the following claims without departing from the invention.

Having thus described my invention, I claim:

1. Lamp assembly means comprising a parabolic reflector having a circular opening therethrough, said opening being laterally enlarged at a plurality of spaced apart places; a cylindrical socket in said opening of substantially the diameter of said opening, the portion of said reflector margining said opening having an inward extension and said socket having a channel therein adapted to receive said inward extension; a bayonet seat in said channel for said extension; lugs on said socket adapted to pass through the lateral enlargements of said opening and to bear against the portion of said reflector margining said opening, said lugs and said seat being spaced apart substantially 120 degrees around the axis of said socket and providing bearing points for the socket on said reflector in a plane perpendicular to the axis of said socket; an incandescent lamp having its base in said Socket and its lighting filament within said reflector, said base having bayonet pins one said pin passing through said channel in said socket and being received in an intermediate seat therein and said other bayonet pin passing through a diametrically opposite channel in said socket and being received in a bayonet seat therein; a lamp contact on said base; a three-legged spring surrounding said socket and keyed thereto, each leg of said spring pressing against said reflector at a point on the opposite surface of said reflector from said bearing points and radially and longitudinally aligned with each of said bearing points; a terminal contact in said socket; means for aligning said terminal contact with said lamp contact; and means for pressing said terminal contact against said lamp contact whereby the circuit is completed and the said bayonet pins are pressed against their said seats. 2. Lamp assembly means comprising a parabolic reflector having an opening therethrough; a

cylindrical socket of substantially the size of said opening positioned therein; interengaging elements between said reflector and said socket distributed around the socket axis at bearing points less than one hundred and eighty degrees apart, said points determining a plane perpendicular to the socket axis; a spring keyed to said socket and having a plurality of free terminations pressing against the reflector at points radially and substantially longitudinally aligned with said interengaging elements but on the opposite side of the reflector from the interengaging elements of the socket; a double pole incandescent lamp in said socket, said lamp having a plurality of lamp contacts and having the center of its bright light producing filament upon the axis of said socket and having bayonet pins receivable in bayonet seats in said socket; spring pressed terminal contacts in said socket pressing said bayonet pins against said seats; means for positively securing alignment of terminal contacts and said lamp contacts; and means for positioning the axis of said lamp coincident with the axis of said socket.

3. Lamp assembly means comprising a concave mounting having a circular opening therethrough; a cylindrical socket in said opening of substantially the diameter of said opening, the portion of said mounting margining said opening having an inward extension and said socket having a channel therein adapted to receive said inward extension; a bayonet seat in said channel for said extension; lugs on said socket adapted to bear against the portion of said mounting margining said opening, said lugs and said seat being spaced apart substantially 120 degrees around the axis of said socket and providing bearing points for the socket on said mounting in a plane perpendicular to the axis of said socket; a spring surrounding said socket and pressing said socket at said bearing points against said mounting, said spring pressing against said mounting at points on the opposite surface of said mounting from said bearing points and radially and longitudinally aligned with said bearing points.

4. The combination with a parabolic reflector having an opening therethrough concentric with the axis thereof; of a cylindrical socket snugly received in said opening from the rear of the reflector; interengaging means between said socket and the forward surface of the reflector brought into operation upon rotation of the socket in said opening and determining a plane perpendicular to the axis of the socket; a spring comprising a plate surrounding the socket and keyed to the rear end of the socket, said spring having a plurality of elliptic legs integral with the plate and said legs having their free ends pressing against the reflector close to the socket at points radially and longitudinally aligned with said interengaging means but upon the opposite surface of the reflector; an incandescent lamp received in the forward end of the socket, said lamp having the lighting center of its filament on its axis and spaced from the reflecting surface of the reflector a distance equal to the distance between the reflector and its focus; and means for maintaining the lamp coaxial with the socket, whereby the lighting center of the filament is maintained coincident with the focus of the reflector.

5. The combination with a parabolic reflector embodying a thin metal shell having an opening therethrough; of a cylindrical socket received in said opening from the rear of the reflector; interengaging means between said socket and at least three points on the forward surface of the reflector brought into operation upon rotation of the socket in said opening and determining a plane perpendicular to the axis of the socket; a spring comprising a plate surrounding the socket and permanently keyed to the rear end thereof against rotation with respect thereto, said spring having -a plurality of elliptic legs integral with the plate and said legs having their free ends pressing against the reflector close to the socket but upon the opposite surface of the reflector from the interengaging means, each of said free ends being radially and longitudinally aligned with one of said interengaging means in a plane parallel tc the axis of the socket, whereby distortion of the reflector is prevented and the axis of the socket is maintained coincident with the axis of the opening.

6. The combination with a parabolic reflector embodying a thin metal shell having an opening therethrough;. of a socket or the like in said opening; abutment means on the socket engaging the forward surface of the reflector at three points substantially equally spaced about the axis of the socket and defining a plane perpendicular to the socket axis; and a spring surrounding the socket at the rear of the reflector and keyed to the socket against both rotative and rearward movements, said spring having a plurality of free elliptic legs, each leg terminating close to the socket and pressing against the rear of the reflector in substantial alignment both radially and longitudinally with one of the abutment means on the socket to clamp the reflector directly therebetween, whereby distortion of the reflector is prevented and the socket axis is maintained coincident with the axis of the opening.

7. The combination with a parabolic reflector embodying a thin metal shell having an opening therethrough; of a socket in said opening; abutments on the socket engaging the forward surface of the reflector at three points spaced apart about the axis of the socket and defining a plane perpendicular to said axis; and a spring surrounding the socket at the rear of the reflector and keyed thereto, said spring having a plurality of free elliptic legs, each leg being bent in a series of reverse curves terminating close to the socket and pressing against the rear of the reflector in a common plane with one of the abutments parallel to the axis of the socket to clamp the reflector therebetween, said spring except at the terminations of its legs being spaced from the reflector, whereby distortion of the reflector is prevented and the axis of the socket is maintained coincident with the axis of the opening.

HARRY A. DOUGLAS. 

